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Biomedical subjects

H Lang

Publications and source records attributed to H Lang.

At least 271 records · Page 15Linked to original sources
PubMed1978

Creatine kinase isoenzyme patterns in Duchenne muscular dystrophy.

Serum creatine kinase isoenzymes were studied in 41 patients suffering from Duchenne type muscular dystrophy and 20 mothers of patients (carriers) by cellulose acetate electrophoresis. Both the MM and MB types were found in all cases of Duchenne type dystrophy patients, and in carriers with highly elevated total creatine kinase activity BB was not observed above the detection limits of the methods used. However, a so-called atypical CK--BB band has been demonstrated.

Creatine Kinase↗
PubMed1977

Quantitative determination of creatine kinase isoenzyme catalytic concentrations in serum using immunological methods.

For the determination of creatine kinase isoenzyme catalytic concentrations in serum two methods based on immunological reactions are presented: One method uses inhibiting antibodies, which selectively block the activity of creatine kinase M subunits ("Inhibition Test"). This test is used for routine measurements of creatine kinase MB catalytic concentration; Another method uses precipitating antibodies, which allows a quantitative differentiation of creatine kinase isoenzymes MM, MB and BB ("Precipitation Test"). This test is used as a control for the Inhibition Test for the possible presence of creatine kinase BB activities in doubtful cases. Procedures, specificity, correlation and application of these methods are discussed.

Creatine Kinase↗
PubMed1977

Kinetic determination of glucose concentrations with glucose dehydrogenase.

A manual version and mechanized versions for several types of analyzers are described for the kinetic determination of glucose with glucose dehydrogenase. Results of glucose determinations with and without deproteinization of samples are discussed. The correlation of results with the hexokinase method is shown.

Alcohol Oxidoreductases↗
PubMed1977

[Thin layer chromatography screening test for semiquantitative detection of 4-hydroxy-3-methoxy mandelic acid (HMMA) in urine without extraction (author's transl)].

A thin layer chromatography (TLC) screening test is described, which allows the semiquantitative determination of HMMA in urine samples. From the collected 24 hour urine a measured sample is applied without extraction to a special TLC plate, which is developed in one dimension. In comparison to a series of graded standard solutions the daily HMMA output can be estimated semiquantitatively. In 102 patients over 18 years of age, suffering from high blood pressure, the daily HMMA output was estimated by both the Pisano method (Pisano, J.J., Crout, J.R. & Abraham, D. (1962), Clin. Chim. Acta 7,285--291) and the TLC method. Coincident results with both methods were obtained in 99 of these cases. The residual 3 cases show pathological results with the Pisano method and results in the normal range or the warning range, respectively, with the TLC method. These cases can probably be classified as false positive results of the Pisano method. The TLC method is recommended as a screening test for estimating the daily HMMA excretion.

Chromatography, Thin Layer↗
PubMed1976

[Molecular mechanisms of the biological effects of UV radiation].

The biological processes taking place in the biosphere are for the largest part bound to the existence of ultraviolet-rays in form of sun rays. Here the furthering effect of the UV-rays on origination, maintenance and further development of life processes is contrasted by the harmful influences of the UV-rays. With the help of the hitherto known facts the primary and consecutive processes which underlie the biological effects of the UV-rays are discussed on molecular level. Furthermore, the possibilities of repairing these lesions caused by UV-rays as well as the biological consequences when repair damages are present are discussed. Finally on the basis of experimental examinations the author deals with the problems of the ultra-violet radiation of the blood.

Bioelectric Energy Sources↗
PubMed1976

[Isoenzymes of creatine kinase in extracardiac disease and after various diagnostic and therapeutic procedures].

Creatine kinase MB isoenzyme was measured (using antibody inhibition) in serum of patients with exogenous intoxication, acute pancreatitis, cerebrovascular accidents, meningitis, encephalitis, skeletal muscle disease, shock, postoperative states and after coronary arteriography, cardiac catherisation of cardioversion. CK-MB activity was revealed only in sera of patients with exogenous intoxication (severity III and IV), polymyositis, scleroderma, after operation or after coronary arteriography, cardiac catherisation or cardioversion. As it is not possible to differentiate between CK-MB and CK-BB using inhibiting antibodies against CK-M subunit, CK-isoenzyme activity was determined in parallel, using precipitating antibodies. No CK-BB was found in any case. The determination of CK-MB isoenzyme after blocking of the CK-MB subunit by means of inhibiting antibodies is suitable for clinical diagnosis. The method significantly increases the value of creatine kinase measurement.

Angiography↗
PubMed1976

[Determination of creatine kinase-MB in serum using inhibiting antibodies (author's transl)].

A new method for the determination of creatine kinase-MB activity in the serum is presented. The principle of this method is the direct measurement of the activity of creatine kinase M subunits by inhibiting antibodies. The total test procedure takes 15 min. In the sera of all the 83 patients tested, who have clinically proven myocard infarction, creatine kinase-MB activity can be measured between the 6th and 28th hour after infarction. At the time of maximum total creatine kinase activity the percentage of creatine kinase-MB activity is between 6 and 17%, the mean value being 8%. In cases of emergency this method can be used for the differential diagnosis of elevated total creatine kinase activities of unknown origin.

Clinical Enzyme Tests↗
PubMed1976

Determination of creatine kinase isoenzyme MB activity in serum using immunological inhibition of creatine kinase M subunit activity. Activity kinetics and diagnostic significance in myocardial infarction.

This is a new method for the determination of creatine kinase isoenzyme MB activity in serum. The method uses direct activity measurement of creatine kinase B subunit activity after blocking of CK-M subunit activity by inhibiting antibodies. The test takes no longer than 15 min. The method yields an intra-serial C.V. of 2.0-12.9%, and a C.V. from day to day of 5.5%. The detection limit is 3.4 U/l creatine kinase MB. In the 95 cases with proven myocardial infarction several types of creatine kinase MB activity kinetics could be determined. The percentage of creatine kinase MB of peak CK-total is 6-25%, with a mean of 11.1%. The amount of creatine kinase MB with respect to total CK activity after reinfarction is higher than the amount after initial infarction.

Antigen-Antibody Reactions↗
PubMed1975

[Determination of creatine phosphokinase-MB in the serum of patients with myocardial infarction by an immunological method (author's transl)].

The immunological method of determining creatine phosphokinase-MB in the serum of patients with myocardial infarction described here is based on the differential measurements of CK-activities before and after a specific immuno-precipitation of the CK-MB type. The minimum activity of the CK-MB-type which it is possible to determine with this method is 4% of the total activity. In patients with clinically confirmed myocardial infarctions 1-15% (mean 7.8%) of the total activity can be calculated as CK-activity of the MB-type on the first/second day(s) after the infarction. In patients with increased total CK-activity and without verified infarction the CK-MB content does not differ significantly from zero. The differences between the two groups are statistically significant. In patients with myocardial reinfarction the CK-MB-activity is higher than that after the first infarction. The immunological method to determine creatine-phosphokinase isoenzyme MB is of differential-diagnostic value in myocardial infarction.

Clinical Enzyme Tests↗
PubMed1975

CD studies of conformational changes of DNA upon photosensitized UV-irradiation at 313 nm.

The role of thymine dimerization for previously reported U.V. induced conformational changes has been proved using acetophenone as sensitizer for the specific thymine dimerization upon irradiation at 313 nm. CD results demonstrate that formation of pyrimidine dimers cause typical conformational changes of the DNA B helix as observed on irradiation at 254 nm. Thus the primary role of adenine photoproducts may be excluded.

Animals↗
PubMed1975

Mechanism of radioactive iodine uptake depression following intravenous urography.

The radioactive iodine (RAI) uptake examination is a standard test for the evaluation of thyroid diseases. For many years it has been known that the results of the RAI are depressed following administration of iodinated contrast media, such as that used for intravenous urography (Williams, 1968; Beierwates, 1956; Slingerland, 1957). The mechanism of this depression is not well documented. It is presumably due to inorganic iodide since it is only inorganic iodide that can be extracted from the blood by the thyroid gland. To study this problem we measured inorganic iodide in bottled contrast media.

Diatrizoate↗
PubMed1975

[A glucose dehydrogenase for the determination of glucose concentrations in body fluids (author's transl)].

The isolation of glucose dehydrogenase from Bacillus megaterium M 1286 is outlined. Data on the specificity of the enzyme towards carbohydrates are given. A specific method for glucose determination using this enzyme was developed. Methods and results of four variants of this glucose determination are presented: End point determination in the UV range, determination with formazan as reaction product, kinetic determination in the UV range, and continuous flow analysis in the UV range (AutoAnalyzer method).

Alcohol Oxidoreductases↗